Biphasic or multiphasic pulse generator and method

ABSTRACT

A dynamically adjustable biphasic or multiphasic pulse generation system and method are provided. The dynamically adjustable biphasic or multiphasic pulse generator system may be used as a pulse generation system for a defibrillator or other type of electrical stimulation medical device.

PRIORITY CLAIMS/RELATED APPLICATIONS

This application is a continuation in part of and claims priority under35 USC 120 to pending U.S. patent application Ser. No. 14/303,541, filedon Jun. 12, 2014 and entitled “Dynamically Adjustable MultiphasicDefibrillator Pulse System And Method” (now published as US 2014-0371805A1) which in turn claims priority under 35 USC 120 and claims thebenefit under 35 USC 119(e) to U.S. Provisional Patent Application Ser.No. 61/835,443 filed Jun. 14, 2013 and titled “Dynamically AdjustableMultiphasic Defibrillator Pulse System and Method” (now expired), theentirety of all of which are incorporated herein by reference.

FIELD

The disclosure relates to medical devices and in particular to devicesand methods that generate and deliver therapeutic treatment pulses usedin medical devices, such as cardioverters and defibrillators,neuro-stimulators, musculo-skeletal stimulators, organ stimulators andnerve stimulators. More specifically the disclosure relates to thegeneration by such medical devices of a new and innovatively shapedbiphasic or multiphasic pulse waveform.

BACKGROUND

It is well known that a signal having a waveform may have a therapeuticbenefit when the signal is applied to a patient. For example, thetherapeutic benefit to a patient may be a treatment that is provided tothe patient. The therapeutic benefit or therapeutic treatment mayinclude stimulation of a part of the body of the patient or treatment ofa sudden cardiac arrest of the patient. Existing systems that apply asignal with a waveform to the patient often generate and apply awell-known signal waveform and do not provide much, or any,adjustability or variability of the signal waveform.

In the context of defibrillators or cardioverters, today's manualdefibrillators deliver either an older style Monophasic Pulse (a singlehigh energy single polarity pulse) or the now more common Biphasic Pulse(consisting of an initial positive high energy pulse followed by asmaller inverted negative pulse). Today's implantable cardioverterdefibrillators (ICDs), automated external defibrillators (AEDs) andwearable cardioverter defibrillators (WCDs) all deliver Biphasic Pulseswith various pulse phase lengths, high initial starting pulse amplitudeand various pulse slopes. Each manufacturer of a particulardefibrillator, for commercial reasons, has their own unique and slightlydifferent exact timing and shape of the biphasic pulse for theirdevices' pulses, although they are all based off of the standardbiphasic waveform design. Multiple clinical studies over the last coupleof decades have indicated that use of these variants of the biphasicwaveform has greater therapeutic value than the older monophasicwaveform does to a patient requiring defibrillation therapy and thatthese standard biphasic waveforms are efficacious at appreciably lowerlevels of energy delivery than the original monophasic waveforms, andwith a higher rate of resuscitation success on first shock delivery.

Thus, almost all of the current defibrillator products that use abiphasic waveform pulse have a single high-energy reservoir, which,while simple and convenient, results in severe limitation on the rangeof viable pulse shapes that can be delivered. Specifically, the second(or Negative) phase of the Biphasic waveform is currently characterizedby a lower amplitude starting point than the first (or Positive) phaseof the Biphasic waveform, as shown in FIG. 4. This is due to the partialdraining of the high-energy reservoir during delivery of the initialPositive phase and then, after inverting the polarity of the waveform sothat the Negative phase is able to be delivered, there is only the samepartially drained amount of energy remaining in the energy reservoir.This lower amplitude starting point constrains and causes the lowerinitial amplitude of the Negative phase of the waveform. The typicalexponential decay discharge is shown by the Positive phase of thewaveform shown in FIG. 4.

The standard biphasic pulse waveform has been in common usage in manualdefibrillators and in AEDs since the mid-1990s, and still results inenergy levels of anywhere from 120 to 200 joules or more being deliveredto the patient in order to be efficacious. This results in a very highlevel of electrical current passing through the patient for a shortperiod of time which can lead to skin and flesh damage in the form ofburns at the site of the electrode pads or paddles in addition to thepossibility of damage to organs deeper within the patient's body,including the heart itself. The significant amounts of energy used foreach shock and the large number of shocks that these AED devices aredesigned to be able to deliver over their lifespan, has also limited theability to further shrink the size of the devices.

WCDs generally need to deliver shocks of 150-200 joules in order to beefficacious, and this creates a lower limit on the size of theelectrical components and the batteries required, and hence impacts theoverall size of the device and the comfort levels for the patientwearing it.

ICDs, given that they are implanted within the body of patients, have tobe able to last for as many years as possible before their batteries areexhausted and they have to be surgically replaced with a new unit.Typically ICDs deliver biphasic shocks of up to a maximum of 30-45joules, lower than is needed for effective external defibrillation asthe devices are in direct contact with the heart tissue of the patient.Subcutaneous ICDs, differ slightly in that they are not in directcontact with the heart of the patient, and these generally deliverbiphasic shocks of 65-80 joules in order to be efficacious. Even atthese lower energy levels there is significant pain caused to thepatient if a shock is delivered in error by the device. Most existingdevices are designed to last for between 5-10 years before theirbatteries are depleted and they need to be replaced.

Another, equally common type of defibrillator is the Automated ExternalDefibrillator (AED). Rather than being implanted, the AED is an externaldevice used by a third party to resuscitate a person who has sufferedfrom sudden cardiac arrest. FIG. 9 illustrates a conventional AED 800,which includes a base unit 802 and two pads 804. Sometimes paddles withhandles are used instead of the pads 804. The pads 804 are connected tothe base unit 802 using electrical cables 806.

A typical protocol for using the AED 800 is as follows. Initially, theperson who has suffered from sudden cardiac arrest is placed on thefloor. Clothing is removed to reveal the person's chest 808. The pads804 are applied to appropriate locations on the chest 808, asillustrated in FIG. 9. The electrical system within the base unit 802generates a high voltage between the two pads 804, which delivers anelectrical shock to the person. Ideally, the shock restores a normalcardiac rhythm. In some cases, multiple shocks are required.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a medical device having a biphasic or multiphasicwaveform generator;

FIG. 2 illustrates a defibrillator medical device with a multiphasicwaveform generator with a plurality of independent subsystems each withits own energy reservoir and energy source;

FIG. 3 illustrates a defibrillator medical device with a biphasicwaveform generator with two independent subsystems each with its ownenergy reservoir and energy source;

FIG. 4 illustrates a standard biphasic pulse waveform where the second(negative) phase of the waveform is smaller in amplitude than that ofthe first (positive) phase of the waveform;

FIGS. 5A, 5B and 5C illustrate different examples of a novel biphasic ormultiphasic pulse waveform generated by the biphasic or multiphasicwaveform generator where the second (negative) phase of the waveform islarger in amplitude than the amplitude of the first (positive) phase ofthe waveform;

FIG. 6 illustrates an embodiment of a biphasic/multiphasic waveformgenerator with a single circuit containing multiple energy reservoirswhich can be dynamically charged separately from a single energy sourceand then discharged through the H-bridge;

FIG. 7 illustrates a biphasic/multiphasic waveform generator with asingle circuit containing multiple energy reservoirs which can bedynamically charged separately and then discharged through an H-bridge;

FIG. 8 illustrates a circuit for adjusting the biphasic or multiphasicwaveform generator system's capacitance;

FIG. 9 diagrammatically illustrates an example of a conventionalexternal defibrillator; and

FIG. 10 illustrates a circuit for adjusting the waveform generatorsystem's resistance/impedance.

DETAILED DESCRIPTION OF ONE OR MORE EMBODIMENTS

The disclosure is applicable to various medical devices including alldefibrillator types: external (manual, semi-automated, and fullyautomated), wearable, implantable and subcutaneous implantable. Inaddition to defibrillators, the medical device may also be cardiovertersand external/internal pacers, as well as other types of electricalstimulation medical devices, such as: neuro-stimulators,musculo-skeletal stimulators, organ stimulators and nerve/peripheralnerve stimulators, whether the devices are external or implantable. Thenovel biphasic or multiphasic waveform generator may be particularlyuseful for any type of defibrillator and examples of the novel biphasicor multiphasic waveform generator system will be described in thecontext of a defibrillator for illustration purposes. It will beappreciated, however, that the novel biphasic or multiphasic waveformgenerator may generate and deliver a much wider range of waveforms thanhas previously been possible in the art (or as shown in the examples)including a new generation/family of novel biphasic or multiphasicwaveforms, as shown in FIG. 5A, FIG. 5B and FIG. 5C. Thus, the novelbiphasic or multiphasic waveform generator has greater utility toexisting devices since it may be used to generate one or more of thisfamily of novel lower energy biphasic pulses. For example, the novelbiphasic or multiphasic waveform generator may be configured to generateand deliver a wide range of the new low energy biphasic or multiphasicwaveforms with varying pulse timings, phase tilts and amplitudes. Suchwaveforms can be used in the various medical devices described above. Inthese devices the pulse generator system may be used to generatetherapeutic treatment pulses and then provide the pulses to a patientusing paddles or pads or other suitable forms of electrodes.

The novel biphasic or multiphasic waveform generator can be embodied ina number of different ways, constituting a range of different potentialcircuit designs all of which are within the scope of this disclosuresince any of the circuit designs would be able to generate and deliver awide range of biphasic and/or multiphasic waveforms including the newfamily/generation of low energy biphasic and/or multiphasic waveformswhere the first phase of the waveform has a lower amplitude than thesecond phase of the waveform.

FIG. 1 illustrates a medical device system 100 having a novel biphasicor multiphasic waveform generator 104. As described above, the medicaldevice system may be any type of defibrillator system or any of theother types of medical devices described above. The medical devicesystem 100 may include a medical device 102 that generates and deliversa novel biphasic or multiphasic pulse waveform 110 to a patient 112. Thenovel biphasic or multiphasic pulse waveform 110 may be a therapeuticpulse, a defibrillation pulse and the like. As shown in FIG. 1, themedical device 102 may include a novel multiphasic or biphasic waveformgenerator 104, an energy source 106 and a control logic 108. The novelmultiphasic or biphasic waveform generator 104 may generate a novelbiphasic or multiphasic pulse waveform 110 using the energystored/generated by the energy source 106.

The novel biphasic or multiphasic pulse waveform 110 may have one ormore first phases and one or more second phases wherein the first andsecond phases may be opposite polarities. In one biphasic waveformexample, the first phase may be a positive phase, the second phase maybe a negative phase and the second phase of the waveform may be largerin amplitude than the amplitude of the first phase of the waveform asshown in FIGS. 5A and 5B. Further, as shown in FIG. 5C, a novelmultiphasic pulse waveform that may be generated by the multiphasic orbiphasic waveform generator 104 is shown in which the biphasic ormultiphasic pulse waveform 110 has more than one first phases and morethan one second phases of the pulse waveform. In the example in FIG. 5C,each first phase has a positive polarity and each second phase has anegative polarity. For example, the amplitude of the second phase may beless than 2500 volts and the first phase would be smaller than thesecond phase. The multiphasic or biphasic waveform generator 104 maydeliver an energy of between 0.1 to 200 joules of energy to a patientduring the first phase and second phase of the generated pulse waveformand an inter-pulse period between the first and second phases. Themultiphasic or biphasic waveform generator 104 may deliver the waveformto the patient during a 2 ms to 20 ms time period.

The control logic unit 108 may be coupled to and/or electricallyconnected to the multiphasic or biphasic waveform generator 104 and theenergy source 106 to control each of those components to generatevarious version of the biphasic or multiphasic pulse waveform 110. Theenergy source 106 may be one or more power sources and one or moreenergy reservoirs. The control logic unit 108 may be implemented inhardware. For example, the control logic unit 108 may be a plurality oflines of computer code that may be executed by a processor that is partof the medical device. The plurality of lines of computer code may beexecuted by the processor so that the processor is configured to controlthe multiphasic or biphasic waveform generator 104 and the energy source106 to generate the biphasic or multiphasic pulse waveform 110. Inanother embodiment, the control logic unit 108 may be a programmablelogic device, application specific integrated circuit, a state machine,a microcontroller that then controls the multiphasic or biphasicwaveform generator 104 and the energy source 106 to generate thebiphasic or multiphasic pulse waveform 110. The control logic unit mayalso include analog or digital switching circuitry when the high voltageswitching component 109 is part of the control logic unit 108.

As shown in FIG. 1, the biphasic or multiphasic pulse waveform 110 maybe delivered to the patient 112 using one or more patient contactdevices. The one or more patient contact devices may be, for example, anelectrode, a wire, a paddle, a pad or anything else that is capable ofdelivering the biphasic or multiphasic pulse waveform 110 to the patient112. To further illustrate a medical device that has the multiphasic orbiphasic waveform generator 104 and the energy source 106, an example ofa defibrillator that has the multiphasic or biphasic waveform generator104 and the energy source 106 is now described in further detail.

FIG. 2 illustrates a defibrillator medical device 10 with a multiphasicwaveform generator with a plurality of independent subsystems each withits own energy reservoir and energy source and FIG. 3 illustrates adefibrillator medical device 10 with a biphasic waveform generator withtwo independent subsystems each with its own energy reservoir and energysource. In an embodiment of the novel multiphasic or biphasic waveformgenerator 104 and the energy source 106, the components may use two ormore physically and electrically distinct subsytems 12, 14 in which eachsubsystem has the waveform generator 104, the energy source 106 and thecontrol logic 108 as shown in FIGS. 2-3. The reservoirs of storedelectrical energy may be in two or more different circuits (see FIG. 2and FIG. 3) that function together in a coordinated fashion in order togenerate and deliver the pulse waveform where each phase of the waveformis produced from a separate reservoir of the stored energy. Thereservoirs of energy may be of the same size/quantity or else of widelydifferent sizes and may be supplied by one or more energy sources.

The energy source 106 is not limited to any particular number of energyreservoirs (such as capacitors) or energy sources (such as batteries).Thus, the medical device system 10 may have a plurality or “n” number(as many as wanted) of subsystems 12, 14 that together can be utilizedto generate the various multiphasic or biphasic waveforms. In theexample embodiments shown in FIG. 2 and FIG. 3, there may be two sides,such as side A and side B as shown, and each side may have one or moreof the subsystems 12, 14 and each subsystem may generate a phase of thepulse waveform to generate the biphasic or multiphasic waveform with oneor more first phases and one or more second phases. The two or moresubsystems 12, 14 permit the system to shape the various characteristicsof first and second phases separately from each other. For example, inone example, the first phase may have a positive polarity and itscharacteristics may be shaped independently of the second phase that mayhave a negative polarity and its characteristics. The above describedfunctions may be accomplished through the use of a fast switchinghigh-energy/voltage switch system as described below. The fast switchinghigh-energy/voltage switch system 109 may be part of the control logicunit 108 or the generator 104.

Each subsystem 12, 14 of each side, as shown in FIG. 2 and FIG. 3, mayhave the control logic and heart rhythm sense component 108 (that isconnected to a similar component on the other side by a digital controllink 30 as shown in FIG. 2 and FIG. 3) that may be also coupled to ahigh voltage switching system component 109. The high voltage switchingsystem component 109 may be implemented using either analog circuits ordigital circuits or even some hybrid of the two approaches. Furthermore,the high voltage switching system component 109 may be implementedthrough the use of mechanical or solid-state switches or a combinationof the two. The energy reservoir may also be coupled, by a high voltagereturn line 32 to the other side of the system as shown in FIG. 2 andFIG. 3. The high voltage return 32 electrically completes the circuitand is present in existing defibrillators, but in a slightly differentform since in the existing style of devices it is split into two partsin the form of the two leads which go from the main defibrillator deviceto the internal or external surface of the patient.

FIGS. 5A-5C illustrate examples of the biphasic or multiphasic waveformsthat may be generated by the systems shown in FIGS. 2-3 as well as thesystems shown in FIGS. 6-8. In the examples in FIGS. 5A-5B a first phasemay be a positive polarity and the second phase may be a negativepolarity. However, the biphasic or multiphasic waveforms also may have anegative polarity first pulse and a positive polarity second pulse. Asshown in FIGS. 5A and 5B, the first phase pulse amplitude may be smallerthan the second phase amplitude. FIG. 5C illustrates a multiphasicwaveform in which the waveform has two or more positive polarity phasesand two or more negative polarity phases.

In another embodiment (see FIG. 6) the system 10 makes use of two ormore reservoirs of stored electrical energy 501 (such as high voltagegenerator and reservoir 1061, high voltage generator and reservoir 1062and high voltage generator and reservoir 106 n) that are eitherstatically or dynamically allocated from within a single circuit 502 andthat function together in a coordinated fashion in order to generate anddeliver the final waveform where each phase of the waveform is producedfrom a separate reservoir of the stored energy. The reservoirs of energy501 may be of the same size/quantity or else of widely different sizesand may be supplied by one or more energy sources. The system 10 mayalso have the high voltage switch 109 for each reservoir 501 and anH-bridge switch 110 that may be part of the control logic unit 108 orthe generator 104. The H-bridge circuit is a known electronic circuitthat enables a voltage to be applied across a load, M, in eitherdirection using one or more switches (seehttp://cp.literature.agilent.com/litweb/pdf/5989-6288EN.pdf that isincorporated by reference herein for additional details about theH-bridge circuit.)

In another embodiment (see FIG. 7) the system makes use of at least onereservoir of stored electrical energy 601 in a configuration that isdivided up and either statically or dynamically allocated into two ormore portions of stored energy 602 from within a single circuit and thatgenerates and delivers the final waveform in a coordinated fashion whereeach phase of the waveform is produced from a separate portion of thestored energy. The portions of energy 602 may be of the samesize/quantity or else of widely different sizes and may be supplied bythe one or more energy sources. Essentially, this involves charging oneor more group(s)/array(s) of capacitors (the number of capacitors in astatically or dynamically created group is based on the voltage andenergy requirements for the phase of the waveform or waveform that is tobe generated and delivered) and then discharging a select number ofcapacitors in a group that is configured as required to provide thedesired waveform or phase of a waveform. The charging and discharging ofcapacitors in parallel and in series is well known in the art. Through aconfiguration of switches (mechanical or solid state) one can disconnecta certain number of capacitors from the original group/array ofcapacitors, thus separating the stored energy into two (or more)portions/reservoirs that feed an H-bridge switch 110, allowing thecreation of a wide range of waveform phases with different amplitudes,shapes and timings.

Another embodiment of the system makes use of a direct currentgeneration source in order to generate the initial phase of the waveformand then uses one or more reservoirs of stored electrical energy inorder to generate the second phase of the waveform and any additionalphases of the waveform. The energy reservoirs used may be supplied byone or more energy sources.

Another embodiment of the system makes use of a direct currentgeneration source in order to generate the initial phase of the waveformand then uses one or more additional direct current generation sources,configured alone, together, or else in combination with reservoirs ofstored electrical energy, in order to generate the second phase of thewaveform and any additional phases of the waveform. The energyreservoirs used may be supplied by one or more energy sources.

In additional embodiments, the pulse generator may be configured withthe circuitry, processors, programming and other control mechanismsnecessary to separately and individually vary the phase timings, theinter-phase pulse timing(s), the phase tilts and the phase amplitudesnecessary to customize and optimize the waveform for the patient at handand for the specific therapeutic purpose for which the waveform is beingused.

The above described functions may be accomplished through the use of afast switching high-energy/voltage switch system 109 which can be eitheranalog or digital in nature or even some hybrid of the two approaches asshown in FIG. 2 and FIG. 3. The switching can be accomplished throughthe use of mechanical or solid-state switches or a combination of thetwo.

Other embodiments of the system discharge part of the waveform's initialphase energy through the use of a statically or dynamically allocatedgroup of resistive power splitters (see FIG. 10), which steps thewaveform's initial phase amplitude down across the group of resistors,and in this manner delivers a smaller remaining amplitude of thewaveform's initial phase to the patient, while still delivering a fullamplitude of the second phase (and any additional phases) to thepatient.

Many embodiments of the system can make use of one or more additionalcircuitry modules or subsystems intended to alter the RC constant of thepulse delivery circuitry for one or more of the pulse phases, and hencealter the tilt of the phase of the pulse waveform involved. Thesemodules or subsystems can consist of an array of capacitors or an arrayof resistors, or of a combination of the two (see FIG. 8 and FIG. 10).

In some embodiments of the system, the system may provide for therecharging of individual energy reservoirs by the energy sources duringtimes (including inter-phase pulse times) that an individual energyreservoir is not selected for discharge. This provides the opportunityto interlace equivalent amplitude initial multiphasic pulses utilizingseveral different high energy reservoirs.

While the foregoing has been with reference to a particular embodimentof the disclosure, it will be appreciated by those skilled in the artthat changes in this embodiment may be made without departing from theprinciples and spirit of the disclosure, the scope of which is definedby the appended claims.

The invention claimed is:
 1. A pulse generator, comprising: a pulsewaveform generator that generates a pulse waveform having at least onefirst phase of the pulse waveform and at least one second phase of thepulse waveform, wherein the first phase has an amplitude whose value isless than an amplitude of the second phase and wherein the first phasehas a polarity and the second phase has an opposite polarity to thefirst phase; at least a first subsystem that generates at least thefirst phase of the pulse waveform, the subsystem having a power sourceand an energy reservoir; at least a second subsystem that generates atleast the second phase of the pulse waveform, the second subsystemhaving a second power source and a second energy reservoir; and acontrol logic unit that controls the first and second subsystems togenerate the pulse waveform having the at least one first phase and theat least one second phase.
 2. The generator of claim 1, wherein thecontrol logic unit further comprises a switching component that switchesbetween the first and second subsystems to generate the pulse waveformhaving the at least one first phase and the at least one second phase.3. The generator of claim 1, wherein the generated pulse waveform has aplurality of first phases and a plurality of second phases to generate amultiphasic pulse waveform.
 4. The generator of claim 1, wherein thegenerated pulse waveform has a single first phase and a single secondphase to generate a biphasic pulse waveform.
 5. The generator of claim1, wherein the generated pulse waveform has the first phase that has apositive polarity and the second phase that has a negative polarity. 6.The generator of claim 1, wherein the generated pulse waveform has thefirst phase that has a negative polarity and the second phase that has apositive polarity.
 7. The generator of claim 1, wherein the generatedpulse waveform has an energy of between 0.1 to 200 joules of energydelivered to a patient during the first phase and second phase of thegenerated pulse waveform and an inter-pulse period between the first andsecond phases.
 8. The generator of claim 7, wherein the energy of thegenerated pulse waveform is delivered to the patient during a 2 ms to 20ms time period.
 9. The generator of claim 1 further comprising anadjustment component that adjusts a slope of at least one phase of thepulse waveform or an amplitude of at least one phase of the pulsewaveform.
 10. The generator of claim 9, wherein the adjustment componentis an array of capacitors wherein one or more capacitors are selected toadjust a slope of at least one phase of the pulse waveform or anamplitude of at least one phase of the pulse waveform.
 11. The generatorof claim 10, wherein the array of capacitors is one of capacitorsconnected in series, capacitors connected in parallel and capacitorsconnected in series and parallel.
 12. The generator of claim 1 furthercomprising an array of capacitors that adjusts a slope of at least onephase of the pulse waveform.
 13. The generator of claim 12, wherein thearray of capacitors is one of capacitors connected in series, capacitorsconnected in parallel and capacitors connected in series and parallel.14. The generator of claim 9, wherein the adjustment component is anarray of resistors wherein one or more resistors are selected to adjusta slope of at least one phase of the pulse waveform or an amplitude ofat least one phase of the pulse waveform.
 15. The generator of claim 14,wherein the array of resistors is one of resistors connected in series,resistors connected in parallel and resistors connected in series andparallel.
 16. The generator of claim 1, wherein the control logic unitadjusts a timing for at least one phase of the pulse waveform.
 17. Thegenerator of claim 16, wherein the control logic unit adjusts the timingfor at least one phase of the pulse waveform based on a heart rhythm ofa patient.
 18. The generator of claim 1, wherein the control logic unitadjusts a timing of an inter-phase period between the first phase andthe second phase of the pulse waveform.
 19. The generator of claim 18,wherein the control logic unit adjusts the timing for the inter-phaseperiod based on a heart rhythm of a patient.
 20. A biphasic ormultiphasic pulse generator, comprising: a pulse waveform generator thatgenerates a pulse waveform having at least one first phase of the pulsewaveform and at least one second phase of the pulse waveform, whereinthe first phase has an amplitude whose value is less than an amplitudeof the second phase and wherein the first phase has a polarity and thesecond phase has an opposite polarity to the first phase; a firstsubsystem that generates at least the first phase and the second phaseof the pulse waveform, the first subsystem having an array of powersources and an array of energy reservoirs that are capable of beingallocated into a first group and a second group in order to separatelygenerate the first and second phases of the pulse waveform using thefirst and second groups, respectively, of the first subsystem; and acontrol logic unit that controls the allocation of the first and secondgroups from the first subsystem to generate the pulse waveform havingthe at least one first phase and the at least one second phase.
 21. Thegenerator of claim 20, wherein the control logic unit further comprisesa switching component that switches between the first group and secondgroup of the first subsystem to generate the pulse waveform having theat least one first phase and the at least one second phase.
 22. Thegenerator of claim 20, wherein the generated pulse waveform has aplurality of first phases and a plurality of second phases to generate amultiphasic pulse waveform.
 23. The generator of claim 20, wherein thegenerated pulse waveform has a single first phase and a single secondphase to generate a biphasic pulse waveform.
 24. The generator of claim20, wherein the generated pulse waveform has the first phase that has apositive polarity and the second phase that has a negative polarity. 25.The generator of claim 20, wherein the generated pulse waveform has thefirst phase that has a negative polarity and the second phase that has apositive polarity.
 26. The generator of claim 20, wherein the generatedpulse waveform has an energy of between 0.1 to 200 joules of energydelivered to a patient during the first phase and second phase of thegenerated pulse waveform and an inter-pulse period between the first andsecond phases.
 27. The generator of claim 26, wherein the energy of thegenerated pulse waveform is delivered to the patient during a 2 ms to 20ms time period.
 28. The generator of claim 20 further comprising anadjustment component that adjusts a slope of at least one phase of thepulse waveform or an amplitude of at least one phase of the pulsewaveform.
 29. The generator of claim 28, wherein the adjustmentcomponent is an array of capacitors wherein one or more capacitors areselected to adjust a slope of at least one phase of the pulse waveformor an amplitude of at least one phase of the pulse waveform.
 30. Thegenerator of claim 29, wherein the array of capacitors is one ofcapacitors connected in series, capacitors connected in parallel andcapacitors connected in series and parallel.
 31. The generator of claim20 further comprising an array of capacitors that adjusts a slope of atleast one phase of the pulse waveform.
 32. The generator of claim 31,wherein the array of capacitors is one of capacitors connected inseries, capacitors connected in parallel and capacitors connected inseries and parallel.
 33. The generator of claim 28, wherein theadjustment component is an array of resistors wherein one or moreresistors are selected to adjust a slope of at least one phase of thepulse waveform or an amplitude of at least one phase of the pulsewaveform.
 34. The generator of claim 33, wherein the array of resistorsis one of resistors connected in series, resistors connected in paralleland resistors connected in series and parallel.
 35. The generator ofclaim 20, wherein the control logic unit adjusts a timing for at leastone phase of the pulse waveform.
 36. The generator of claim 35, whereinthe control logic unit adjusts the timing for at least one phase of thepulse waveform based on a heart rhythm of a patient.
 37. The generatorof claim 20, wherein the control logic unit adjusts a timing of aninter-phase period between the first phase and the second phase of thepulse waveform.
 38. The generator of claim 37, wherein the control logicunit adjusts the timing for the inter-phase period based on a heartrhythm of a patient.
 39. A method for generating a therapeutic pulsewaveform, comprising: generating at least one first phase of a pulsewaveform using at least a first subsystem having a power source and anenergy reservoir to generate the at least one first phase; generating atleast one second phase of the pulse waveform using at least a secondsubsystem having a second power source and a second energy reservoir togenerate the at least one second phase, wherein the at least one firstphase of the pulse waveform is smaller in amplitude than the amplitudeof the at least one second phase of the pulse waveform and wherein thefirst phase has a polarity and the second phase has an opposite polarityto the first phase; and controlling a selection of the at least onefirst phase and the at least one second phase to generate the pulsewaveform having the at least one first phase and the at least one secondphase.
 40. The method of claim 39, wherein controlling the selection ofthe at least one first pulse and the at least one second pulse furthercomprises switching, using a switching component, between at least onefirst phase and the at least one second phase to generate the pulsewaveform.
 41. The method of claim 39, wherein the generated pulsewaveform has a plurality of first phases and a plurality of secondphases to generate a multiphasic pulse waveform.
 42. The method of claim39, wherein the generated pulse waveform has a single first phase and asingle second phase to generate a biphasic pulse waveform.
 43. Themethod of claim 39, wherein the generated pulse waveform has the firstphase that has a positive polarity and the second phase that has anegative polarity.
 44. The method of claim 39, wherein the generatedpulse waveform has the first phase that has a negative polarity and thesecond phase that has a positive polarity.
 45. The method of claim 39,wherein the generated pulse waveform has an energy of between 0.1 to 200joules of energy delivered to a patient during the first phase andsecond phase of the generated pulse waveform and an inter-pulse periodbetween the first and second phases.
 46. The method of claim 45, whereinthe energy of the generated pulse waveform is delivered to the patientduring a 2 ms to 20 ms time period.
 47. The method of claim 39 furthercomprising adjusting a slope of at least one phase of the pulse waveformor an amplitude of at least one phase of the pulse waveform.
 48. Themethod of claim 39 further comprising adjusting a timing for at leastone phase of the pulse waveform.
 49. The method of claim 48, whereinadjusting the timing for at least one phase of the pulse waveformfurther comprises taking a heart rhythm from a patient and adjusting thetiming for at least one phase of the pulse waveform based on the heartrhythm of the patient.
 50. The method of claim 39 further comprisingadjusting a timing of an inter-phase period between the first phase andthe second phase of the pulse waveform.
 51. The method of claim 50,wherein adjusting the timing of the inter-phase period further comprisestaking a heart rhythm from a patient and adjusting the timing of theinter-phase period based on the heart rhythm of the patient.